This website first appeared December 6, 2009

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Northwest Geology Field Trips, by Dave Tucker, is licensed under a Creative Commons Attribution-Noncommercial- Share Alike 3.0 United States License. You can use what you find here, repost it with attribution to the author, "remix" it for your own purposes, but may not use it with the intent of making money off of it.

EDUCATORS: Please feel free to use anything you find here that is useful to your mission educating people about Earth science. E-mail me if it would help to have a larger or higher-resolution version of any of the images. tuckerd at geol dot wwu dot edu

The mammoth Aldergrove erratic is in Aldergrove, British Columbia, just 1/2 mile north of the US-Canada border. This erratic is 36 feet x 40 feet (10.8 x 12 m) at the base, and all of 26 feet (nearly 8 m) tall. It’s weight has been estimated at 3500 tons (3,175,130 kg). The Aldergrove erratic squats on the southern slope of a Sumas stade glacial moraine, the last advance during the Fraser Glaciation to reach as far south as the border region. Here is another fine example of conglomerate from the Jackass Mountain Group, which is found in the Hope, BC- Manning Park area. See the story on the Donovan Avenue erratic for more on this rock; the Ferndale erratics are also Jackass conglomerate. This distinctive rock really got around! Look carefully to see the rounded cobbles of igneous rocks that make up much of the conglomerate; these are pretty sure indicators of the Jackass rock. The Aldergrove erratic has been much abused by painters- gray paint daubed over graffiti has obscured the rock’s texture, to head height or more. There are a pair of hefty belay anchors on the top, but scrambling to the top requires some nerve if you aren’t a practiced rock climber- and remember, it is easier to go up than to climb back down! If you get stuck, don’t blame this website!

There are nice trails in the Regional Park- pick up a map at the entrance just north of the erratic parking area. A short walk to the south along the gravel trail beside the erratic gives nice views southeast and east to the Twin Sisters, Mount Baker, Shuksan, and the Lucky Four Range.

October, 2012– The Sto:lo (the People of the River) have a name for this hulking, elongated rock. According to Albert ‘Sonny’ McHalsie , Cultural Advisor/Historian at the Stó:lō Research and Resource Management Centre, in the Halq’emeylem language the name for ths erratic is “meqsel”, meaning “nose”. In the story, a man was constantly sneezing, which is a sign of impending disaster. Xexa:ls, who were the transformers (the 3 bear brothers and 1 sister who traveled through the land to make the world right) transformed his nose to stone. The Xexa:ls transformed the Sto:lo ancestors into mountains or rocks.

Getting there: The erratic is on Lefeuvre Road, along the east edge of Aldergrove Lake Regional Park. From Aldergrove BC, take Highway 13 south toward the Lynden-Aldergrove border crossing. Go east on 8 Ave (aka Huntingdon Road). In 2 miles (3.2 km) turn south on Lefeuvre Road. In 1/2 mile (0.8 km) the hulking erratic will appear on the west side of the road; park on the shoulder. From the USA, take Guide Meridian (WA 539) north from I-5 in Bellingham. Go through Lynden and cross the border. Don’t forget your passport! Immediately after Canadian customs, turn right on O (‘zero’) Ave and head east. The shallow ditch on your right is the International boundary, with video monitors and Border Patrol surveillance. 1.75 miles from the border crossing, turn north on Lefeuvre Road- the erratic is 0.4 miles up the road on your left. To return to the USA, you must continue north 1/2 mile to 8 Ave, go west to 13, then south to the border.